When a loved one has Alzheimer's disease, time takes on new significance. Every day that he or she can hold onto old memories or stay out of a nursing home becomes a gift. Thanks to new treatments and a growing understanding of the disease, families and patients can enjoy more of those gifts than ever before. For some patients, new drugs can delay the advance of the disease for months, or even years. Meanwhile, families everywhere are learning how to keep their loved ones as healthy as possible for as long as possible. It's called buying time, and it's hard to think of a better investment.

A slow road

The progression of Alzheimer's disease is usually slow, but ultimately devastating. For reasons that have so far eluded scientists, the brain of a person with Alzheimer's gradually develops strange deposits of tangles (twisted protein fibers inside brain cells, or neurons) and sticky plaques outside those cells. Studies now suggest that the disease is caused by the shrinkage and death of brain cells and their synapses, rather than the actual plaques and tangles. The latest thinking is that the abnormal processing of a normally harmless protein called beta-amyloid triggers a set of events that causes the neurons to shrink and die.

These changes in the brain soon lead to subtle changes in the person. Long before receiving the diagnosis of Alzheimer's disease, a person may feel his memory is slipping away. He may stumble over familiar words, miss appointments, or lose things more often than usual. Within a few years, someone with Alzheimer's may get lost in familiar neighborhoods. Eventually, even simple tasks such as cooking and dressing normally become a challenge. By this time, many friends and family members aren't surprised when a doctor finally makes the diagnosis of Alzheimer's disease.

As the years go by, Alzheimer's disease will tighten its grip. Patients start to forget basic facts, from the current year to the names of their siblings. No matter what course the disease follows, patients and their families have the same goal: Hold on to the good times for as long as possible. The longer a person can do things for himself, the longer he can enjoy his favorite activities, and the longer he can maintain some independence while living with his family, the better it is for everyone.

Exercise Rx for Alzheimer's

In late 2010, scientists from the University of Pittsburgh released a study that suggested walking about five miles a week may help slow the progression of Alzheimer's disease and a condition called Mild Cognitive Impairment, which often precedes AD.

"We found that walking five miles per week protects the brain structure over 10 years in people with Alzheimer's and MCI, especially in areas of the brain's key memory and learning centers," said Cyrus Raji, of the university's department of radiology, in a news release. "We also found that these people had a slower decline in memory loss over five years."

Sadly, walking is not a cure for the disease. "But walking can improve your brain's resistance to the disease and reduce memory loss over time," 

Indeed, even healthy people without any symptoms of mental decline may be able to help ward off Alzheimer's disease by walking a similar amount each week, although the research showed they needed to walk a little more: about six miles weekly.

The findings were preliminary, and Dr. Robert Friedland, chairman of the neurology department at the University of Louisville's School of Medicine in Kentucky, told reporters that it was important not to assume walking was the cause of reduced risk. Instead, it could be that people with Alzheimer's simply tend to walk less. That said, he noted there were many reasons walking might be protective against Alzheimer's, including improving blood flow to the brain.

Indeed, some of the best therapies around can't top good old-fashioned exercise, said Eric Larson, MD, a professor of medicine at the University of Washington in Seattle. A simple 30-minute walk around the neighborhood every day (with a caregiver, of course) can help slow the "downward spiral" of Alzheimer's in other ways, he said.

In a study of Alzheimer's patients published in the Journal of the American Medical Association, Larson and colleagues found that a three-month exercise program improved physical functioning, eased depression, and helped keep people out of nursing homes. Larson has seen similar results many times in his practice, and he knows how much these improvements can mean to patients and their families. Exercise greatly prolongs the time that patients can get out of bed by themselves, he said. It also helps them burn the nervous energy that could otherwise lead to nighttime wandering and other troubling behaviors. As a result, patients sleep better at night, which is a triumph for the whole family.

Any type of walking will do the trick, whether it's a lap around the neighborhood or 30 minutes on a treadmill. Still,  it's hard to beat a stroll outdoors. The patient gets some fresh air and a chance to get reacquainted with the surroundings, and, just as important, caregivers (who often have trouble getting exercise themselves) get a chance to be physically active, too. A daily walk, can also help undo some of the stress of caregiving.

So with your doctor's blessing, walk with your loved one up to five miles a week, if possible (and try to work in that extra mile per week for yourself).